Thanks for the support---seems like I really won't have to buy a new router, the WNR2000 is doing great once I figured out how to set it!!
I changed the "mode" setting, which is quite generic, from "Up to 145Mbps" which according to the directions, was the "default setting" and would "allow all 11b and 11g and 11n wireless stations", to "Up to 300Mbps". It also notes "up to 145" is the "Neighbor Friendly Mode", so I am guessing it has also increased its transmit power now?
Its flying right along now, speeds in the 15-18Mbps range which is outstanding. Before, the downloads were choppy, and had many hesitations, which are all completely gone now. I'm amazed, actually, that it made such a difference!
I think the "help" page could use some help itself, and explain things the way mozerd
did, which made it obvious that the ability to support "b" devices would negatively impact everything else. I never would have known that before, as I surely thought "up to 145" would be plenty!